gecko-dev/media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp

557 lines
18 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <stdint.h>
#include <stdio.h>
#include "ClearKeyDecryptionManager.h"
#include "ClearKeyUtils.h"
#include "ClearKeyStorage.h"
#include "ClearKeyPersistence.h"
#include "gmp-task-utils.h"
#include "mozilla/Assertions.h"
#include "mozilla/NullPtr.h"
using namespace mozilla;
using namespace std;
class ClearKeyDecryptor
{
public:
ClearKeyDecryptor(GMPDecryptorCallback* aCallback, const Key& aKey);
~ClearKeyDecryptor();
void InitKey();
void QueueDecrypt(GMPBuffer* aBuffer, GMPEncryptedBufferMetadata* aMetadata);
uint32_t AddRef();
uint32_t Release();
const Key& DecryptionKey() const { return mKey; }
private:
struct DecryptTask : public GMPTask
{
DecryptTask(ClearKeyDecryptor* aTarget, GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
: mTarget(aTarget), mBuffer(aBuffer), mMetadata(aMetadata) { }
virtual void Run() MOZ_OVERRIDE
{
mTarget->Decrypt(mBuffer, mMetadata);
}
virtual void Destroy() MOZ_OVERRIDE {
delete this;
}
virtual ~DecryptTask() { }
ClearKeyDecryptor* mTarget;
GMPBuffer* mBuffer;
GMPEncryptedBufferMetadata* mMetadata;
};
struct DestroyTask : public GMPTask
{
explicit DestroyTask(ClearKeyDecryptor* aTarget) : mTarget(aTarget) { }
virtual void Run() MOZ_OVERRIDE {
delete mTarget;
}
virtual void Destroy() MOZ_OVERRIDE {
delete this;
}
virtual ~DestroyTask() { }
ClearKeyDecryptor* mTarget;
};
void Decrypt(GMPBuffer* aBuffer, GMPEncryptedBufferMetadata* aMetadata);
uint32_t mRefCnt;
GMPDecryptorCallback* mCallback;
GMPThread* mThread;
Key mKey;
};
ClearKeyDecryptionManager::ClearKeyDecryptionManager()
{
CK_LOGD("ClearKeyDecryptionManager ctor");
// The ClearKeyDecryptionManager maintains a self reference which is
// removed when the host is finished with the interface and calls
// DecryptingComplete(). We make ClearKeyDecryptionManager refcounted so
// that the tasks to that we dispatch to call functions on it won't end up
// derefing a null reference after DecryptingComplete() is called.
AddRef();
}
ClearKeyDecryptionManager::~ClearKeyDecryptionManager()
{
CK_LOGD("ClearKeyDecryptionManager dtor");
MOZ_ASSERT(mRefCount == 1);
}
void
ClearKeyDecryptionManager::Init(GMPDecryptorCallback* aCallback)
{
CK_LOGD("ClearKeyDecryptionManager::Init");
mCallback = aCallback;
mCallback->SetCapabilities(GMP_EME_CAP_DECRYPT_AUDIO |
GMP_EME_CAP_DECRYPT_VIDEO);
ClearKeyPersistence::EnsureInitialized();
}
void
ClearKeyDecryptionManager::CreateSession(uint32_t aCreateSessionToken,
uint32_t aPromiseId,
const char* aInitDataType,
uint32_t aInitDataTypeSize,
const uint8_t* aInitData,
uint32_t aInitDataSize,
GMPSessionType aSessionType)
{
CK_LOGD("ClearKeyDecryptionManager::CreateSession type:%s", aInitDataType);
// initDataType must be "cenc".
if (strcmp("cenc", aInitDataType)) {
mCallback->RejectPromise(aPromiseId, kGMPNotSupportedError,
nullptr /* message */, 0 /* messageLen */);
return;
}
if (ClearKeyPersistence::DeferCreateSessionIfNotReady(this,
aCreateSessionToken,
aPromiseId,
aInitData,
aInitDataSize,
aSessionType)) {
return;
}
string sessionId = ClearKeyPersistence::GetNewSessionId(aSessionType);
MOZ_ASSERT(mSessions.find(sessionId) == mSessions.end());
ClearKeySession* session = new ClearKeySession(sessionId, mCallback, aSessionType);
session->Init(aCreateSessionToken, aPromiseId, aInitData, aInitDataSize);
mSessions[sessionId] = session;
const vector<KeyId>& sessionKeys = session->GetKeyIds();
vector<KeyId> neededKeys;
for (auto it = sessionKeys.begin(); it != sessionKeys.end(); it++) {
if (!Contains(mDecryptors, *it)) {
// Need to request this key ID from the client.
neededKeys.push_back(*it);
} else {
// We already have a key for this key ID. Mark as usable.
mCallback->KeyIdUsable(sessionId.c_str(), sessionId.length(),
&(*it)[0], it->size());
}
}
if (neededKeys.empty()) {
CK_LOGD("No keys needed from client.");
return;
}
// Send a request for needed key data.
string request;
ClearKeyUtils::MakeKeyRequest(neededKeys, request, aSessionType);
mCallback->SessionMessage(&sessionId[0], sessionId.length(),
(uint8_t*)&request[0], request.length(),
"" /* destination url */, 0);
}
void
ClearKeyDecryptionManager::LoadSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
CK_LOGD("ClearKeyDecryptionManager::LoadSession");
if (!ClearKeyUtils::IsValidSessionId(aSessionId, aSessionIdLength)) {
mCallback->ResolveLoadSessionPromise(aPromiseId, false);
return;
}
if (ClearKeyPersistence::DeferLoadSessionIfNotReady(this,
aPromiseId,
aSessionId,
aSessionIdLength)) {
return;
}
string sid(aSessionId, aSessionId + aSessionIdLength);
if (!ClearKeyPersistence::IsPersistentSessionId(sid)) {
mCallback->ResolveLoadSessionPromise(aPromiseId, false);
return;
}
// Callsback PersistentSessionDataLoaded with results...
ClearKeyPersistence::LoadSessionData(this, sid, aPromiseId);
}
void
ClearKeyDecryptionManager::PersistentSessionDataLoaded(GMPErr aStatus,
uint32_t aPromiseId,
const string& aSessionId,
const uint8_t* aKeyData,
uint32_t aKeyDataSize)
{
if (GMP_FAILED(aStatus) ||
Contains(mSessions, aSessionId) ||
(aKeyDataSize % (2 * CLEARKEY_KEY_LEN)) != 0) {
mCallback->ResolveLoadSessionPromise(aPromiseId, false);
return;
}
ClearKeySession* session = new ClearKeySession(aSessionId,
mCallback,
kGMPPersistentSession);
mSessions[aSessionId] = session;
uint32_t numKeys = aKeyDataSize / (2 * CLEARKEY_KEY_LEN);
for (uint32_t i = 0; i < numKeys; i ++) {
const uint8_t* base = aKeyData + 2 * CLEARKEY_KEY_LEN * i;
KeyId keyId(base, base + CLEARKEY_KEY_LEN);
MOZ_ASSERT(keyId.size() == CLEARKEY_KEY_LEN);
Key key(base + CLEARKEY_KEY_LEN, base + 2 * CLEARKEY_KEY_LEN);
MOZ_ASSERT(key.size() == CLEARKEY_KEY_LEN);
session->AddKeyId(keyId);
if (!Contains(mDecryptors, keyId)) {
mDecryptors[keyId] = new ClearKeyDecryptor(mCallback, key);
}
mDecryptors[keyId]->AddRef();
mCallback->KeyIdUsable(aSessionId.c_str(), aSessionId.size(),
&keyId[0], keyId.size());
}
mCallback->ResolveLoadSessionPromise(aPromiseId, true);
}
void
ClearKeyDecryptionManager::UpdateSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength,
const uint8_t* aResponse,
uint32_t aResponseSize)
{
CK_LOGD("ClearKeyDecryptionManager::UpdateSession");
string sessionId(aSessionId, aSessionId + aSessionIdLength);
auto itr = mSessions.find(sessionId);
if (itr == mSessions.end() || !(itr->second)) {
CK_LOGW("ClearKey CDM couldn't resolve session ID in UpdateSession.");
mCallback->RejectPromise(aPromiseId, kGMPNotFoundError, nullptr, 0);
return;
}
ClearKeySession* session = itr->second;
// Parse the response for any (key ID, key) pairs.
vector<KeyIdPair> keyPairs;
if (!ClearKeyUtils::ParseJWK(aResponse, aResponseSize, keyPairs, session->Type())) {
CK_LOGW("ClearKey CDM failed to parse JSON Web Key.");
mCallback->RejectPromise(aPromiseId, kGMPInvalidAccessError, nullptr, 0);
return;
}
for (auto it = keyPairs.begin(); it != keyPairs.end(); it++) {
KeyId& keyId = it->mKeyId;
if (!Contains(mDecryptors, keyId)) {
mDecryptors[keyId] = new ClearKeyDecryptor(mCallback, it->mKey);
mCallback->KeyIdUsable(aSessionId, aSessionIdLength,
&keyId[0], keyId.size());
}
mDecryptors[keyId]->AddRef();
}
if (session->Type() != kGMPPersistentSession) {
mCallback->ResolvePromise(aPromiseId);
return;
}
// Store the keys on disk. We store a record whose name is the sessionId,
// and simply append each keyId followed by its key.
vector<uint8_t> keydata;
Serialize(session, keydata);
GMPTask* resolve = WrapTask(mCallback, &GMPDecryptorCallback::ResolvePromise, aPromiseId);
static const char* message = "Couldn't store cenc key init data";
GMPTask* reject = WrapTask(mCallback,
&GMPDecryptorCallback::RejectPromise,
aPromiseId,
kGMPInvalidStateError,
message,
strlen(message));
StoreData(sessionId, keydata, resolve, reject);
}
void
ClearKeyDecryptionManager::Serialize(const ClearKeySession* aSession,
std::vector<uint8_t>& aOutKeyData)
{
const std::vector<KeyId>& keyIds = aSession->GetKeyIds();
for (size_t i = 0; i < keyIds.size(); i++) {
const KeyId& keyId = keyIds[i];
if (!Contains(mDecryptors, keyId)) {
continue;
}
MOZ_ASSERT(keyId.size() == CLEARKEY_KEY_LEN);
aOutKeyData.insert(aOutKeyData.end(), keyId.begin(), keyId.end());
const Key& key = mDecryptors[keyId]->DecryptionKey();
MOZ_ASSERT(key.size() == CLEARKEY_KEY_LEN);
aOutKeyData.insert(aOutKeyData.end(), key.begin(), key.end());
}
}
void
ClearKeyDecryptionManager::CloseSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
CK_LOGD("ClearKeyDecryptionManager::CloseSession");
string sessionId(aSessionId, aSessionId + aSessionIdLength);
auto itr = mSessions.find(sessionId);
if (itr == mSessions.end()) {
CK_LOGW("ClearKey CDM couldn't close non-existent session.");
mCallback->RejectPromise(aPromiseId, kGMPNotFoundError, nullptr, 0);
return;
}
ClearKeySession* session = itr->second;
MOZ_ASSERT(session);
ClearInMemorySessionData(session);
mCallback->ResolvePromise(aPromiseId);
mCallback->SessionClosed(aSessionId, aSessionIdLength);
}
void
ClearKeyDecryptionManager::ClearInMemorySessionData(ClearKeySession* aSession)
{
MOZ_ASSERT(aSession);
const vector<KeyId>& keyIds = aSession->GetKeyIds();
for (auto it = keyIds.begin(); it != keyIds.end(); it++) {
MOZ_ASSERT(Contains(mDecryptors, *it));
if (!mDecryptors[*it]->Release()) {
mDecryptors.erase(*it);
mCallback->KeyIdNotUsable(aSession->Id().c_str(), aSession->Id().size(),
&(*it)[0], it->size());
}
}
mSessions.erase(aSession->Id());
delete aSession;
}
void
ClearKeyDecryptionManager::RemoveSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
string sessionId(aSessionId, aSessionId + aSessionIdLength);
auto itr = mSessions.find(sessionId);
if (itr == mSessions.end()) {
CK_LOGW("ClearKey CDM couldn't remove non-existent session.");
mCallback->RejectPromise(aPromiseId, kGMPNotFoundError, nullptr, 0);
return;
}
ClearKeySession* session = itr->second;
MOZ_ASSERT(session);
string sid = session->Id();
bool isPersistent = session->Type() == kGMPPersistentSession;
ClearInMemorySessionData(session);
if (!isPersistent) {
mCallback->ResolvePromise(aPromiseId);
return;
}
ClearKeyPersistence::PersistentSessionRemoved(sid);
// Overwrite the record storing the sessionId's key data with a zero
// length record to delete it.
vector<uint8_t> emptyKeydata;
GMPTask* resolve = WrapTask(mCallback, &GMPDecryptorCallback::ResolvePromise, aPromiseId);
static const char* message = "Could not remove session";
GMPTask* reject = WrapTask(mCallback,
&GMPDecryptorCallback::RejectPromise,
aPromiseId,
kGMPInvalidAccessError,
message,
strlen(message));
StoreData(sessionId, emptyKeydata, resolve, reject);
}
void
ClearKeyDecryptionManager::SetServerCertificate(uint32_t aPromiseId,
const uint8_t* aServerCert,
uint32_t aServerCertSize)
{
// ClearKey CDM doesn't support this method by spec.
CK_LOGD("ClearKeyDecryptionManager::SetServerCertificate");
mCallback->RejectPromise(aPromiseId, kGMPNotSupportedError,
nullptr /* message */, 0 /* messageLen */);
}
void
ClearKeyDecryptionManager::Decrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
CK_LOGD("ClearKeyDecryptionManager::Decrypt");
KeyId keyId(aMetadata->KeyId(), aMetadata->KeyId() + aMetadata->KeyIdSize());
if (!Contains(mDecryptors, keyId)) {
CK_LOGD("ClearKeyDecryptionManager::Decrypt GMPNoKeyErr");
mCallback->Decrypted(aBuffer, GMPNoKeyErr);
return;
}
mDecryptors[keyId]->QueueDecrypt(aBuffer, aMetadata);
}
void
ClearKeyDecryptionManager::DecryptingComplete()
{
CK_LOGD("ClearKeyDecryptionManager::DecryptingComplete");
for (auto it = mSessions.begin(); it != mSessions.end(); it++) {
delete it->second;
}
mSessions.clear();
for (auto it = mDecryptors.begin(); it != mDecryptors.end(); it++) {
delete it->second;
}
mDecryptors.clear();
Release();
}
void
ClearKeyDecryptor::QueueDecrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
CK_LOGD("ClearKeyDecryptor::QueueDecrypt");
mThread->Post(new DecryptTask(this, aBuffer, aMetadata));
}
void
ClearKeyDecryptor::Decrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
if (!mThread) {
mCallback->Decrypted(aBuffer, GMPGenericErr);
}
// If the sample is split up into multiple encrypted subsamples, we need to
// stitch them into one continuous buffer for decryption.
vector<uint8_t> tmp(aBuffer->Size());
if (aMetadata->NumSubsamples()) {
// Take all encrypted parts of subsamples and stitch them into one
// continuous encrypted buffer.
unsigned char* data = aBuffer->Data();
unsigned char* iter = &tmp[0];
for (size_t i = 0; i < aMetadata->NumSubsamples(); i++) {
data += aMetadata->ClearBytes()[i];
uint32_t cipherBytes = aMetadata->CipherBytes()[i];
memcpy(iter, data, cipherBytes);
data += cipherBytes;
iter += cipherBytes;
}
tmp.resize((size_t)(iter - &tmp[0]));
} else {
memcpy(&tmp[0], aBuffer->Data(), aBuffer->Size());
}
MOZ_ASSERT(aMetadata->IVSize() == 8 || aMetadata->IVSize() == 16);
vector<uint8_t> iv(aMetadata->IV(), aMetadata->IV() + aMetadata->IVSize());
iv.insert(iv.end(), CLEARKEY_KEY_LEN - aMetadata->IVSize(), 0);
ClearKeyUtils::DecryptAES(mKey, tmp, iv);
if (aMetadata->NumSubsamples()) {
// Take the decrypted buffer, split up into subsamples, and insert those
// subsamples back into their original position in the original buffer.
unsigned char* data = aBuffer->Data();
unsigned char* iter = &tmp[0];
for (size_t i = 0; i < aMetadata->NumSubsamples(); i++) {
data += aMetadata->ClearBytes()[i];
uint32_t cipherBytes = aMetadata->CipherBytes()[i];
memcpy(data, iter, cipherBytes);
data += cipherBytes;
iter += cipherBytes;
}
} else {
memcpy(aBuffer->Data(), &tmp[0], aBuffer->Size());
}
mCallback->Decrypted(aBuffer, GMPNoErr);
}
ClearKeyDecryptor::ClearKeyDecryptor(GMPDecryptorCallback* aCallback,
const Key& aKey)
: mRefCnt(0)
, mCallback(aCallback)
, mThread(nullptr)
, mKey(aKey)
{
if (GetPlatform()->createthread(&mThread) != GMPNoErr) {
CK_LOGD("failed to create thread in clearkey cdm");
mThread = nullptr;
return;
}
}
ClearKeyDecryptor::~ClearKeyDecryptor()
{
CK_LOGD("ClearKeyDecryptor dtor; key ID = %08x...", *(uint32_t*)&mKey[0]);
}
uint32_t
ClearKeyDecryptor::AddRef()
{
return ++mRefCnt;
}
uint32_t
ClearKeyDecryptor::Release()
{
uint32_t newCount = --mRefCnt;
if (!newCount) {
if (mThread) {
// Shutdown mThread. We cache a pointer to mThread, as the DestroyTask
// may run and delete |this| before Post() returns.
GMPThread* thread = mThread;
thread->Post(new DestroyTask(this));
thread->Join();
} else {
delete this;
}
}
return newCount;
}